Safety mechanism for pressure cookers



June 3, 1952 c. c. SCHWEISO 2,599,072

SAFETY MECHANISM FOR PRESSURE COOKERS Filed May 3, 1948 4 Sheets-Sheet 1.INVENTOR CLIFFORD C. SCHWEISO BY W A TTY June 3, 1952 Filed May 3, 1948C. C. SCHWEISO SAFETY MECHANISM FOR PRESSURE COOKERS 4 Sheets-Sheet 2 4443/42l,35 36 33 x I y/i/LM; C. glue/4 A TTY June 3, 1952 c. c. SCHWEISOSAFETY MECHANISM FOR PRESSURE COOKERS 4 Sheets-Sheet 3 FIG. 4

Filed May 3, 1948 FlG.-5

INVENTOR CLIFFORD C. SCHWEESO AT Y.

June 3, 1952 c. c. SCHWEISO SAFETY MECHANISM FOR PRESSURE COOKERS 4Sheets-Sheet 4 Filed May 3, 1948 INVENTOR CLIFFORD C. SCHWEISO 141% W 4ATTX Patented June 3, 1952 UNITED STATES PATENT OFFICE SAFETY MECHANISMFOR PRESSURE COOKERS Cliflord C. Schweiso, Minneapolis, 7 Minn., as-

signor to General Mills, Inc., a corporation of Delaware Application Maya, 1948, Serial No. 24,764

19 Claims.

prior art for attachment of the cover to a pressure cooker. Many ofthese forms fail to provide safety means to prevent removal of the coverwhen the container is under pressure. Other constructions which doattempt to provide such safety means are complicated in structure andexpensive to manufacture.

Accordingly, one object of this invention is to provide a pressurecooker which will overcome these disadvantages of the prior art.

Another object of the invention is to provide improved means forattachment of the cover to a pressure cooker.

A further object is the provision of a readily constructed safetymechanism to prevent removal of said cover while there is still pressureinside the cooker.

Still another object is the provision of improved fastening means for acover of the type which can be positioned and latched loosely on thecooker body and which subsequently engages said body to form a tightclosure in response to a predetermined change in a cooking conditionwithin the cooker.

A further object is the design of improved latching means for the coverof a pressure cooker, in which pressure from within the cooker willincrease the force which holds said latching means in its lockingposition.

Anadditional object of the invention is the construction of improvedlatch operating means for the cover of a pressure cooker, in which theuser of the cooker will be unable to exert substantial leverage to openthe latch when there is pressure inside the cooker.

Other objects and advantages of this invention willbe apparent from thefollowin detailed de- 7 Various methods have been proposedin the 2position, certain parts being broken away and others being shown in fulllines for clearness.

Fig. 3 is a view similar to Fig. 2 but with the cover in sealedposition.

Fig. 4 is a detail view of certain parts of the device of the precedingfigure.

Fig. 5 is a perspective view of one form of operating handle accordingto this invention.

Fig. 6 is a perspective view of a handgrip for the device of Fig. 5.

Fig. '7 is a partial view of a modified fastening" mechanism accordingto the present invention, applied to a cooker which has a difierent formof cover construction from that of Figs. 1 to 6';

Fig. 8 is a perspective view of the latch meminvention, includes theusual body portion 20.,

which may be of any desired shape and external design. I prefer asubstantially cylindrical pot as shown in Fig. l. A handle extension 21may be made integral with said body portion or may be separatelymanufactured and attached thereto by welding or other suitable means. Ahandle 22 of plastic or other desired heat-insulating material isfastened on the handle extension 2| and extends preferably horizontallyand radially from the upper portion of the body to furnish a convenientand accessible grip for the hand of the user. i

The top of the cooker body 20 is provided with an opening 50;surrounding this opening is a suitable annular seat 23 shaped tocooperate with the cover means to be described below.

The cover 24 may be of any desired construction adapted to engage saidseat from the outside and maintain tight sealing engagement therewith atelevated temperatures and pressures and at the same time flex slightlyupward at its center in response to a cooking condition within thecooker. Since pressure and temperature have a definite correlation, oncethe air has been vented, it is possible to utilize either pressure ortemperature or both to cause this flexing of the cover.

less steel while plate 49 consists of that type of nickel alloy steelknown as Invar. Thus, if the cover is heated, due to increase intemperature of the cooker bodyand contents, the cover 24 will tend tobendor fiex downwardlytowardthe.

seat 23 to establish a firm seal with said seat and prevent escape ofthe steam formed within the cooker body. At the same time, sincedownwardmovement of the edges of the cover is-limi-ted by 7 seat 23, thecentral portion of the cover will" tend to flex upwardly. This upwardflexing will be further assisted by the upward force onsa'id The sealingaction of the cover may be facilitatedby the useiof a gasket 25 of anydesired construction. The gasket'shown inthe drawing i'sl mad'e'fofsynthetic rubberor similar resilient ma teri'al suitably resistant totheconditiens encounteredrduring operation of the cooker; andprovidedwith a' thin downwardly-projecting lipas shown, which willbeipressed tightly against-the seat by; internalpressure after'r-theinitial seal is established. r v

The cover is' carried by a--su-itabIeF-suppoi;ting

member shown in the shape of a bridge orcross bar ZHQPQSitiOIlEdfexternally of the" cover 24' and the opening 50', and extendingsubstantially diametricallyi across said opening. The crossbar 26- andcover 24 'are connected together-so that the position'and movement *ofthe cover will be: determined by. the" position 'and movement of the"crossbar; In the example'showm-this fastening is at the center of thecover.

The crossbar and cover may carry: asuitable pressure control memberthe-' fornlmfia pres sure weighti'l'of' any desired-construction. Thepressure control =member is adapted to permit escape of"-'ste amwhen-theinternal pressur'ef reaches-a predetermined value; and- -itnrayalsoinclude .a pressure gauge; 3 4" from which the user can ascertainith"specific --pressure -"condit'ions' withinzthe; cooker at any time;--suchmembers are known inthe art; and need-not be described in'detailzinV 'At one endof the external bridge or crossbar 26cooperatingmeans areprovidedto hold "the end of the crossbar in operative position with revspect: tothe cooker body; This-eooperatingmeans includes" adownwardextension "28 on the cross bar 26; said extension having'an inwardlyturned hook 28 for engagement-with a recess-swimmethickenedportion-3l ofthe-cooker-bddy. 'A" -positioning iug 3-2 on' the underside of-thecrossbar at endcooperate'swith the flatsurface 51 of {the cookerbod'y tohold the crossbar and cover= in'thcirpreliminary positions priortosealing of:

thecover'. 1

5 similar; positioning lug 33- is-carried by-thecrossbar at a pointwhich will cooper-ate with the fl'at' surf-ace 52-fnear the" handleef=the= pressure cookefbodyg Cooperating-latchmeans are -prov idedon-tlie cooker body andmrossbar ata point near -thebodyhandle- 22- tolatch the crossbar and coverin' position and topermit ready -re'mova-landat tachment- 'ofthe cover; The spe'eificdatch meansnotchesare-provided-in athickened portionofth' cooker bodyimmediatelyadjacentto'--th' E ihu. g i V inward spacing of='-the pivoti as shownat' theyarenearer-the latch =-pi vo 4 It will be readily seen that member 35 ismovable-between two positions;namely the position of'Fig. "I in'which'the latching hooks 3'8" are out of engagement with the retainingsurface 39 and that shown in Figs. 2 and 3 wherein the surfaces38iare-in-position for actual engagement with the retaining surfaces 39to prevent removal of the cover from the crossbar.

; According to this' invention, I have provided specialsafety'meansrtoprevent, movement of said latch member from closed to open positionwhile thereis pressure within the cooker. These safety means will now bedescribed in detail.

The hooks 38 and surfaces 39 are preferably flat and in substantiallythe same planes when latched in :order j to provide l close frictional:contact betweenv these vpart's whi'ch will tend to men sist :movement ofthe :latch to its open postman when the. cover: is exposed tointernal-pressure and exertsan upward force on said =crossbar due to:its. upward flexing aspreviously describe Since the frictional forceresisting laterahslid ingmovement between two surfacesaisf directlyi'proportional to. the force exerted perpendicularly to hold thesurfaces'againstreaclr otheneits wili be: apparent v that. an increaseon. internal #pressure will tend to liftzthe-z center: .015tlietcoverandcross-:1 barv and will iurgersuriaces 4:3:81tandnwcintoigsuch: tight:engagement with each-,otlrer thaizconsidsc erable: force would .be;requirediato: :overcome the: friction and-move. thez-latclr'3fii-tozi-ts'aopenwr un-v latchedposition; a 1

This resistance of tlrexpartsiatoi nnlatchingp when there is internal;.press'ure;,.= is. further sini; creased by positioning thepivot:3Eiat'a point-on;-

the crossbar ssomewhatinsidetthez pointaattwhich. a line perpendiculanto: the; plane of zsurfacesfia and- 39 at their icentertawouldmtersectssaid crosse bar. This spacing is shown by thmdoubleaarrowst- Abetween dotted lines V5: 5 "and: fi-i-li otuFigcA.

Stated in. another: way; the'; tipsw53x-zdfi: latching, hooks 38" shouldbe closer to; the: centemofi pirot 36 than are the inner edges 54 ofsaidii'hooksv While this eff'ect can be achieved eithensbyspositioningthe pivot aszdescribed ore-bye upwardinse clination ofrsurfacesfifiianda39 toward-the eenter;.:- I .prefer the; constructionshownnimWhlCI'IJiSlmE-l faces 38- and 3.9:remain::substaintiallyrhdrizontalzsince this arrangement makes iteeasier toipositiorr and remove thecover.

Thus,; when internal: pressure om the; eover..- 24 lifts the crossbar,to the: positiomshownzirr :Fig'zsiifl the, surfaces 38; andx39: mayexentra- .sliglrtmame; mmg' action on latch member iii-which" tendsito:

i urge the latch more. tightlyrintozlo'ckingengagesz ment with.:re.cess4w; TheLg'reateHthezinternal pressure;thezrgreater;thiscammingactioncwilhbes It w ill be readilymnderstooctthatsh'ooks- 3=8 and retaining surfaces; 39scouldhe formed atkanydelvsired angle \to fit -the above genera However, I have found:thaton'ly' ming' action is required 'to preventf uniatc ing whileinternallpressure is present; and this cam ming action can be obtainedwith only slight-- In order-to-move theiatclr member-35f m"'G1'e'position to the other; *I' have provided serene h member with suitable'n'otches deart -sizedoperating with lugs 43bn-an-*operating handledesignated generally 2,5 41.

The lack of leverage is further emphasized the handle construction andmen"n-ting. Notches massacrestransmitteditozhooksisfinanisappliedtonotches 42; because of. the lowleverage on mechanical disadvantage of this arrangement." a

The handle 41 may consistof twoipartsnarnely a-metalibbdy member il(Fig.5) and? a plastic handgripzfl dFigz .6): which telescopes ontomembrane: Itzwill be? seen fro'mvFig: 2; that. the extem'aL crossbar-1Fhas: an. integral handle ex tension: 46 extending just: above. andsubstantiany parallel. to: the 'liandleaextension' 2! of the cookerbody; The. handle body member 44,, accordingrl. to this: invention is:Channel-shaped as shown imFig. hand is pivotedat 45-to thiscrossbar-extension by: wsuitable screw or rivet. Handgrip 64" isrecessed to fit closely over the Outer; end1tof: member 44 and thenencloses and.

conceals/both member. and handle extension 46; This; arrangement 'isneat and compactin appearance, and. also increases the safety factorfistdiscussed. below. Grip- 64-may be similar to therplastic.Ora-insulated.g-rip 22. on. handle extensioni-i; Raised-portions-or: knurlings 65maybe provided-rat each side of this grip 64- to enable the; user. tograsp. the inner. end of the handle. When.-the.cover is. inplace',,handle 41 may be just-.above-bodyhandle 22 and-parallel to itySOthatbothhandlesmay be. gripped. readily in one hand-by theuser. Point45,- atwhich thishandle 41 is. pivoted to the crossbar, is.substantially spaced-outwardly; from thepivot 36 of the latch member.35.. I prefer. to. position this point 45 at the extreme outer end of(body member 44 and extension.46..' 'I'hus, it.wil1.be seen that thelatch membercan be. actuated between its two positions bylaisi'ngandl'owerin the. inner end of the handl'e. 4T1immediately adjacent tosaid latch member. shown in Fig. 2;..the extension 46 narrows inwardlyfrom pivot 45 to permit limited movement 'of'member 44 on said pivot.Upward movement of'member-Mis limited by contact of edge5'5.of'extension against central portion 56 of member, while downwardmovement is similarly limited by contact of edge 51 against th'e upperinside face 58jof'l'1o1low handgrip 64. Spring means maybe provided, ifdesired. to retain said latch against accidental movement from eitherpfits two positions;

'Imtlienormal process-of gripping handles 47 andthe'thumband'forefinger-of the user will beatthe inner end of the'handle41 in a position to'operate'said handle and latch. Since the outer endof handle member is'fi'xed to the handle extension, andsince anyupwardforce against the. handlefextension 'orcrossbarmerely serves to tightenthe engagement-of'latchmember 35 with recess-40 it is apparent, that theuser cannot exertany' substantial leverage to open the latch. 'Ihestmnger-arm and'shoulder muscles will be ineifective and" only therelatively weaker muscles of the thumb, fi'nger-and'wrist can be used toactuatethe latch 35-.

Furthermore; in the preferred form of my invention'as'shown in thesedrawings, the operating'handleifl lies substantially adjacent the bodyhandle 22. Thus; there no room for the users fingersxto pass betweenthese. handles and obtain a-grip on handle 41. The only natural andpractical method for'the user is to pinch the sides ofthje-inner' end ofhandle "between the thumb a Id.,,f'or efinger and thus lift the handleto operate thielatch; It is apparent that this furtherfeatureoffbonstruction increases the safety factor andfmakesitimpossiblefor the user to exert substantial force or leverage to open.the latch.

ltshould. also henoted. that the handle 41 projeets only a; distanceoutwardly beyomr pivot 55., this distance;beingsubstantiallw than thedistance: fromrpivotfifiitm lateheengagieingjlugsii Thus, antattemptztoopenztheilaltiih by squeezing: this: extreme. outer. portion: bodyhandle 22will. bei'equally. unsucte'ssfulgnsz long? as; there: issubstantial pressures inside the? cooker; because-of thelackofyleveraget;

The frictional; locking? force, the. camm' gL tion of hooks 38-; theengagementxof with the latch at a point nearrthe-latclr. pivot? andthe:relativearrangement of therhandlecpiuott handgrip portion andlatch-engaging; portion; each contribute to thesafety of the.'device:--'1he combination of a plurality; of: these? features: makes it.imp'oss'ible 'for theuser to open thefrlatehi: and remove the-coveruntil-thepressure vet the cooker has been lowered to'arsafe d greeeither by operation'of valve.- -21- or otheriventing means well known inthe art, or by cooling of the; cooker and contents sufficiently tocause;relaxation of cover 2.4 to substantially itswunsealedfpoe sition asshown in'F-ig. 2. V v The operation of this-device can now beelfifidily.understood with referenceto the foregoingbrils?- tural features anddescription: The cover is; placed in position on thecookerby-fi-rst-eng-agingi the hook 29 in the recess 30 while the coveiscrossbarare held substantially in the position shown in Fig. l. Thehandle end of said cross. bar can then beswung down toward bodys 22until the supporting lugs 32 and33 on the flat surfaces 5| and 520ithecooker As the handle 4'1- completes itsmovementtowa handle 22, thelatch. 35 will be rotated to theims sition shown in Fig. 2.

. After the cooker and its contents are.-,hea edj the cover 24'willexpand or flexdownwardlglat. its edges-and the gasketIBwill-beseatedstightlys against the annular seat 23. As furt-her-heataisapplied, the cover will continuetoflex: and will exert an upward forceat the center ofthe crossbar 26- as previously described. Thisiwillliftthe crossbar so that the supporting lugs-32. and -33 are no longerresting on the surfaeeshil and 52. This position of the cookeris...shown. in Fig. 3 from which it will be apparent-that the ho0k29 andthe latch-inghook38;wil1.'.noivr be in tight engagement with theirrespective-Area taining surfaces in the recesses-Mand- 40;. The safetymeans. previously described will" rnalrehit; well nigh impossible forthe-:user-to. .open the. latch and be injured by-suddeneiectionof he:cover or escapeof steam until thepressure the.

.in the container has again been reduced to a I safe degree.

. in temperature or pressure withinthe contai While I have shown thepreferredrembodimentof my. invention in Figs. l-to.6,..in;connectionwith a cooker having a bimetallicv cover,.it:.will be readily apparentto those skilled in theiart. that I. may use any other typeof-cover...which. tends to flex or expand: with referenceiatlie. cookerbody to form atight'seal andexert an upwardforce on crossbar26.1duetoanincrease.

latches, one pivoted at each side of bar 26.

7 body 20, crossbar 26 and handle-operating mechanism are identical withthe similar features shown in the embodiment discussed above.

The annular seat 60 at the top of the cooker body includes asubstantially vertical portion 6| and a relatively sloping inner portion62. These two portions form a'sort of tapered recess into which asuitable gasket 66 on the edge of the cover will be forced to formatight seal when 7 cover 53 is applied. This sealing effect is increasedby internal pressure on the thin, downwardly projecting gasket lip, asin the previous embodiment.

Cover 63 is fastened in its center to crossbar 26. In this particularembodiment of the invention the cover and gasket will fit closelyagainst the seat when the cover is in latched position on the pot, theslight flexing of the cover and gasket being sufficient to efiect aninitial mechanical seal.

'Lugs fil on the crossbar 2B serve to limit the inward movement of thecrossbar to prevent crossbar 26 just as in the case of the embodimentpreviously described. As pressure builds up within the cooker, suchpressure will further tend to lift the center of the cover. Because ofthe dome-like shape, and the resulting inclination of the edges of thecover, such pressure will force the edges more tightly against wallportion 6| of seat 60 and will thus maintain a tight seal. Y

It will be apparent that the operation of the latching mechanism and ofthe safety features previously described will be the same in this caseas in the device of Figs. 1-6.

As shown in Fig. 8, the latch member so far described consists of twoidentical sides connected by an integral crossbar 59, each side havingits own latching hook 38, notch 42 and pivot hole 36. 7

It will be apparent that a single latch member could be used, or thatcrossbar 59 could be omitted, so that there would be two separate Such aseparate latch member is shown in Fig. 9. Obviously two such latcheswould be actuated as a unit by lugs 43 on handle 41, so that omission ofcrossbar 59 would not change the operation of the latching mechanism inany way.

, :Although this latching mechanism and handle construction is ofparticular advantage when according to my invention, various equivalent.

modifications will be apparent to those skilled in the art. Accordingly,my invention is not 8 to be limited by the specific mechanical detailsof construction shown but only by the spirit and scope of the attachedclaims.

Now, therefore, I claim:

1. In a pressure cooker comprising a body having an opening therein, ahandle for said body extending outwardly therefrom, a'cover for saidopening, and a crossbar supportingsaid cover and having a handleextension projecting outwardly substantially adjacent and parallel tosaid body handle when the cover is moved into position to close saidopening, the combination of automatic means for movement of a portion ofthe cover and said crossbar outwardly to a slightly displaced positionin response to a predetermined change in a cooking condition within thecooker, cooperative latching means on said crossbar and said bodyincluding a latch mounted on the crossbar and movable between an openposition in which it permits disengagement of said crossbar and coverfrom the body and a closed position in which it prevents suchdisengagement and limits said outward movement of the crossbar, andsafety means preventing movement of said latch from closed to openposition when said crossbar is held in said displaced position as aresult of said predetermined change, said safety means includingcooperating cam surfaces on said latch and said body urging said latchinto closed posi-- tion when said crossbar is forced toward saiddisplaced position, said safety means also including an operating handlefor said latch having its outer end pivoted to the outer end of saidhandle extension and its inner end engaging said latch and mounted alongthe inner portion of said handle extension for limited movement awayfrom said body handle to actuate said latch from closed to openposition, said operating handle engaging said latch at a point on saidlatch which is nearer said latch pivot than said cam surfaces are.

2. A pressure cooker according to claim 1 in which the automatic meanscomprises a bimetallic cover portion movable to displaced position inresponse to a predetermined change in temperature within the cooker.

3. A pressure cooker according to claim 1 in which the automatic meanscomprises a flexible cover portion having a high thermal coefficient ofexpansion and movable to displaced position in response to apredetermined change in temperature and pressure within the cooker.

4. A pressure cooker including a body member having an opening therein,a bi-metallic cover for said opening, a portion of which is adapted toflex outwardly in response to temperature and pressure, a supportingmember for said cover movable to a slightly displaced position byoutward flexing of said cover portion, a latch mounted on one of saidmembers and movable between an open position in which its permitsdisengagement of said support and cover from the body and a closedposition in which it prevents such disengagement and limits movement ofthe support to said displaced position, and safety means preventingmovement of said latching means from its closed to its open positionwhile said supporting member is in its displaced position, the safetymeans comprising an operating handle pivoted to said one member at apoint spaced from the latch and having an actuating portion engaging thelatch and a main hand grip portion. substantially the entire hand gripportion. being nearer the handle pivot point than is the latch engagingportion. V V

5. A pressure cooker including a body member having an. opening therein,a cover member for said opening, a supporting member for said cover,said cover including temperature responsive means for movement of thecover into sealing engagement. with said opening at a predeterminedtemperature and for moving said supporting member outwardly to adisplaced position in response to further increase of temperature, alatch mounted on one of said members and movable between an openposition permitting disengagement of said supporting member and coverfrom the body and a closed position preventing such disengagement andlimiting the outward movement of said supporting member, and safetymeans preventing movement of said latching means from its closed to itsopen position while said supporting member is held in its displacedposition as .a result of said increase of tempera- 'ture, the safetymeans comprising an operating handle pivoted to said one member at apoint spaced from the latch and having an actuating portion engaging thelatch and a main hand grip portion, substantially the entire hand gripportion being nearer the handle pivot point than is the latch engagingportion.

.6. A'pressure cooker including a body member having an opening therein,a resiliently flexible metallic cover having a high thermal coefiicientof expansion for sealing said opening and flexing a portion of the coveroutwardly in response to a predeterminedpressure. a supporting memberfor said cover movable to a slightly displaced position by outwardflexing of said cover portion, a latch mounted on one of said member andmovable between an open position in which it permits disengagement ofsaid support and cover from the body and a closed position in which itprevents such disengagement but permits movement of the support to saiddisplaced position, and safety means preventing movement of saidlatching'means from its closed to its open position while saidsupporting member is in its displaced position, the safety meanscomprising an operating handle pivoted to said one member at a pointspaced from the latch and having an actuating portion engaging'the latchand a main hand grip portion, substantially the entire hand grip portionbeing nearer the handle pivot point than is the latch engaging portion.

7; A pressure cooker including a body member having an opening therein,a cover for said opening, a supporting member for said cover, said coverincluding automatic means for movement of the cover into sealingengagement with said opening and for moving said supporting memberoutwardly to a slightly displaced position in response to apredetermined change in at least one condition selected from the, groupconsisting of temperature and pressure, a latch mounted on one of themembers and movable between an open position in which it permitsdisengagement of said support and cover from the body and a closedposition in which it prevents such disengagement and limits said outwardmovement of the supporting member and safety means preventing movementof said latching member from its closed to its open position while saidsupportingmember is held in said displaced position as a result of saidpredetermined condition, the safety means comprising an operating handlepivoted to saidone member at a point spaced from the latch and having anactuating portion engaging the latch and a main hand grip portion,substantially the entire hand grip portion being .10 nearer the handlepivot point than is the latch engaging portion.

8. A pressure cooker including a body member having an opening therein,a cover member for said opening having a portion which is'movable to aslightly displaced position in response to a predetermined change in acooking condition within the body, a latch mounted on one of the membersand movable between an open position in which it permits disengagementof said cover from the body and a closed position in which it preventssuch disengagement and limits movement of the cover portion to saiddisplaced position, and safety means preventing movement of saidlatching means from its closed to its open position while said coverportion is in its displaced position, the safety means comprising anoperating handle pivoted to said one member at a point spaced from thelatch and having an actuating portion engaging the latch and a mainhandgrip portion, substantially the entire handgrip portion being nearerthe handle pivot point than is the latch engaging portion.

9". In a pressure cooker comprising a body member having an openingtherein and a cover member for said opening, the combination offastening means including a latch pivoted to one of said members andmovable between an open position in which it permits disengagement ofsaid cover from said body and a closed position in which it preventssuch disengagement, and safety means preventing movement of said latchfrom closed to open position while there ispressure within the cooker,said safety means including cooperating cam surfaces on said latch andthe other of said members urging said latch into closed position inresponse to pressure within the cooker tending to open said cover, anoperating handle pivoted'to said one member at a point substantiallyspaced from said latch pivot, said operating handle having a portionengaging said latch ata point on the latch which is nearer the latchpivot than said cam surfaces are, formovement of said latch by saidlatch engaging portion, and a main hand grip portion on said operatinghandle between said handle pivot and said latch engaging portion,whereby less force is transmitted to the cam surfaces than is applied tothe grip portion. V

10. In a pressure cooker comprising a body member having an openingtherein and a cover member for said opening, the combination offastening means including a latch pivoted to one ofsaid members andmovable between an open position'in which it permits disengagement ofsaid cover from said body and a closed position in which it preventssuch disengagement, and safety means preventing movement of said latchfrom closed to open position while there is pressure within said cooker,said safety means including cooperating cam surfaces on said latch andthe other of said members urging said latch into closed position inresponse to pressure within the cooker tending to open said cover, andan operating handle pivoted to said one member at a point substantiallyspaced from said latch pivot, said operating handle having a portionengaging said latch for movement of the latch and a handgrip portionsubstantially the entire hand grip portion being nearer said handlepivot than is'said I than is applied to the

